The subject matter disclosed herein relates to aircraft. More specifically, the subject disclosure relates to fuel bladder structures for aircraft.
Aircraft, such as airplanes, helicopters, turbo props and tilt rotor aircraft typically often include one or more flexible containers, or bladders, for storage of fuel on board the aircraft. The bladder provides a sealed volume for the storage of fuel as an alternative to forming a sealed chamber in the aircraft structure. Mounting the bladder in such a chamber is typically difficult and costly. The bladders include fittings and/or connections for filling the bladder with fuel, outputting the fuel to an aircraft engine, and may also include ancillary components such as fuel pumps and fuel filters and vent fittings.
In a typical aircraft, most often a helicopter, the bladders are contained in sponsons, or projections from the fuselage of the aircraft. As such, the fuel bladders are contained in a space external to the fuselage and do not negatively impact cargo or passenger space in the aircraft. Further, the external location allows for easy access for installation and mounting of the fuel bladders into the sponsons.
In some instances, when installing a fuel bladder in the sponson, the bladder is placed in the sponson and secured into position by string. The bladder includes a plurality of eyelets or similar structure at a top of the bladder, and possibly at other locations around the exterior of the bladder. The interior of the sponson includes a plurality of complimentary mounting locations, and one or more strings or other are looped through the eyelets and the complimentary mounting locations of the sponson to secure the fuel bladder into position in the sponson.
In some aircraft, however, sponsons are not present or useable for installation of a fuel bladder. Thus a fuel bladder, if utilized, must be installed internal to the fuselage. In many cases, the location chosen for the bladder is surrounded by significant structure, such as keels, bulkheads, decks, etc., which do not allow access to the top, and sometimes even the sides of the bladder for installation by the typical string and loop method or other existing methods for mounting a bladder.